London Homebuilders Delay Project Starts Amid Persistent Slump

In a sign of growing caution, London homebuilders are taking significantly longer to break ground on new developments, even after securing planning approval. According to data from property broker Knight Frank, the typical gap between full planning permission and construction start extended to a record 16.3 weeks in 2024—a 31% increase compared to the previous year and more than 80% longer than in 2018 Business Times.

Looking at the broader timeline, projects in the capital are now taking around 26 months on average to move from initial planning applications to construction—up by 8% year-on-year and just over a week longer than six years ago Business Times. Planners attribute much of this slowdown to ongoing capacity constraints within local planning departments and mounting pressure associated with delivering affordable housing. The knock-on effect of higher mortgage costs, stamp duties, and shifting tax policies impacting buy-to-let investors has eroded developer confidence and weakened demand Business Times.

The latest figures paint a bleak picture for London's housing market. In the first half of 2025, only 3,950 new homes were sold, the lowest volume since 2010 Business Times. To stay afloat, some developers are adjusting expectations. Persimmon, among the UK’s largest homebuilders, has signaled rising optimism that improving mortgage conditions and government-led efforts to ease planning bottlenecks will revive sales through the rest of the year and into 2026 Business Times.